Air-cooled muffler



Nov. 21, 1944. P E FLUOR 2,363,236

AIR-cooLED MUFFLER Filed Aug. 13, 1943 i /9 4/ Z liz f 6k-4 A :1 Z'

Hirn H una@ IN1/EN im.

Patented Nov. 21, 1944 AIR-COOLED MUFFLER Peter E. Fluor, Santa Ana,Calif., assignor to The Fluor Corporation, Ltd., Los Angeles, Calif., acorporation of California Application August 13, 1943, Serial No.498,601

13 Claims.

This invention has to do with mulllers for internal combustion engines,and in certain of its particular aspects, is concerned with improvementsin air-cooled or induced draft muiller assemblies, in which the muillerproper is enclosed within an outer shell or conduit through whichair-flow is induced by the discharge of gas from the muiller.

One major object of the invention is to provide a solution for a longstanding and dimcult problem of properly muilling the exhaust gasimpulses and sounds from Diesel or other two-cycle engines, as well asfrom four-cycle engines. It appears that because of the slower frequencyof the exhaust gas discharges from the individual cylinders infour-cycle engines, the problem of mullling the sound has been lessditlicult, and various designs of muillers have been made to operatesatisfactorily. Muffling of two-cycle engines, however, presents greaterdifficulties and, insofar as I am aware, entirely satisfactory muillingof such engines, at least of the heavier `duty sizes, has notsatisfactorily been accomplished, especially by a muffler suitable forboth four-cycle and vtwo-cycle engines. Extensive tests have shown thatmuiilers of the present design and construction perform at higheiliciency with either type of engine.

Another important feature and object of the invention, applicableparticularly to vertical muillers, is the provision of a drain systemfor removing from within the mulller, particularly when the engine isnot operating, water entering through the top, as during rains or underother circumstances, or where the muiller is used on a boat and water attimes may wash into the muiller. In accordance with the invention,provision is made for arresting the flow of such water into the exhaustpipe and for draining the water from the muiller shell, as well asthrough the enclosing stack or air conduit where the muffler is used inan induced draft assembly.

The manner in which the aforementioned objects are accomplished, andvarious additional featuresand details best explained and understood byreference to a specific embodiment of the invention, will be describedin the following. Reference is had to the accompanying drawing, inwhich:

Fig. 1 is a cross-section view showing a typical induced draft verticalmuler assembly embodying the invention: and

Fig. 2is a cross-section on line 2-2 of Fig. 1.

The muiiler, generally indicated at I 0, is shown III to comprise anouter cylindric shell I I, a top cone I2 having an outlet I3, and abottom cone I4 connected to the exhaust pipe I5 extending from theengine, conventionally indicated at I6. The shell II contains aplurality of concentric, annularly spaced bailles Il, I8, and I9,interconnected by spiders 20, the assembly of baffles beingconcentrically spaced and supported within the shell I I by spiders 2 I.The baffle assembly is closed at the top by a head 22 welded to theouter baffle I'I and against which the intermediate baffle I8terminates. The top and bottom ends of baflles I9 and I8 are spacedrespectively from the head 22 and plate 23, and baille Il extends thefull distance between the head and plate, to cause gas flow along theinner bailles and nally outwardly through the perforations of the outerbaffle as later more specifically considered.

The baille assembly is supported on an inclined oor or drain plate 23having a central opening 24 through which gas discharged from theexhaust pipe I5 into the enlarged chamber 25, enters the innermostbaffle I9. To obtain an initial dispersion and batlling of the gasesflowing from chamber 25 into passage 26, a spider 2l, or other suitablebaille means, may be placed at the inlet side of the opening 24. Accessmay be had to the chamber 25 for inspection or other purposes by Way ofpipe 28 extending through the cone and stack, the outside of theinspection passage normally being closed by a removable cover 29.

In the type of induced draft installation shown, the muiller Il) isenclosed within an outer conduit or stack 30 including a cylindric shellsection 3|, cone 32 and nipple 33 and a bottom cone 34 connecting with acontinuing jacket or conduit 35 surrounding the exhaust pipe I5. Themufller IIl is suitably supported within the outer shell, as by spiders36, to maintain the muiller outlet I3 in such predetermined relation tothe stack throat 3l' that the exhaust gas discharge into the throatinduces high velocity flow of air along the exhaust pipe and about themuiller through passages 38 and 39. Air may enter the conduit 35 at anysuitable location, as at its open end near the engine. Suitableprovision may be made for permitting expansion of the exhaust pipe belowthe fixed muiller, as by including in the exhaust pipe a section I5amade of suitable flexible material.

An important feature contemplated in the operation of the muilierproper, is the arrangement of the perforated bailles Il', I8, and I9 ina er causing the exhaust gases to iiow longi= tudlnally within and'between the bellies, and at the same time to now transverselythroughthe baille: apertures, to the end thatthe gases are required toaeV extended reversing straight path lines or now while subjected to theeects of transverse streams` passing through the bams apertures. Thegases flowing upwardly through passage 26 reverse their path in owingdownwardly through passage tl, and again reverse their ow upon enteringpassage 62 'from which the gases are discharged into space i3 through`the apertures in the outer baille il. Admixed with the gases flowingthrough passages lll and i2 are portions of the gas streams passing outthrough the apertures in baii'les it and i9. It is found that despiteits emcient muing eiect on the gases, the baille assembly imposes verylow back pressure on the engine.

' Although all the reasons for the efilcient operation of the muillerhave not fully been determined, it is believed that the results are duelargely to the capacity oi the baie assembly for permitting passage tothe outlet lt within each interval of exhaust gas discharge from theengine, of substantially the entirety oi a quantity of escasas 'theoutlet to' pass both vlongitudinally between `the bellies and throughthebame perforations, vmeans for introducing vgas into one end of theinnermost baille, and an imperforate closure for the opposite end ofthebaize assembly an end of each of said bailies being open so that the gasflows from said inlet longitudinally through the innermost name and thenreversely and longitudinally through the space between said innermostbaille and the next outer baille.

3. A muiiler comprising a shell having an inlet and an outlet, and abaille assembly within the Ashell including a plurality of spacedtubular permeans conning the discharge of gas from said gascorresponding to the volume of gas accompanying each discharge, andwithout any gaps" between the successive gas discharges through the mueras would otherwise tend to create intermittent pulsations or back ows.Not only is such continuity of the gas discharge important from thestandpoint of sound muling, but also in producing a more constantuniform induction or air, at correspondingly increased rate, throughpassages 38 and 39 in response to the gas discharge from the muiner.

A further important feature is the provision of a controlled drain forremoving from the muler, water entering it under such circumstances aspreviously mentioned.

Any water entering the mufter through the outlet i3 is deiected by thehead 22 into space d3 so that the water collects upon and drains to thebottom of the inclined plate 23. The water then is drained from themuler through the outer shell Si, by way of pipe 35 carrying a valve d6or other suitable closure. When the engine is not in operation, valve d@may be left open so that any water entering the mulder will beimmediately drained to the outside. During engine operation the valve ofcourse will be closed. As will be observed, the position of plate 23 andits association with the drain pipe, electively prevent the water fromreaching the gas inlet l5 and entering the exhaust pipe.

I claim:

1. A muliier comprising a shell having an inlet and an outlet, and abaiile assembly within the shell including a plurality of spaced tubularperforated baies one within the other and arranged to cause gases owingfrom said inlet to the outlet tc pass both longitudinally between thebaiiles and through the baille perforations an end of each of saidbaiiles being open so that the gas ilows from said inlet longitudinallythrough the innermost baille and then reversely and longitudinallythroughl the space between said innermost baille and the next outerbaille.

2. A muliier comprising a shell having an inlet and an outlet, and abaflle assembly within the shell including a plurality of spaced tubularperforated ballles one within the other and arranged to cause gasesflowing from said inlet to baille assembly to the perforations of theouter= most bale an end of each of said baffles being open so that thegas flows from said inlet longitudinally through the innermost bailleand then reversely and longitudinally through the space between saidinnermost bams and the next outer baiile.

4. A muiler comprising a shell having an inlet and an outlet, and labattle assemblywithin the shell including a plurality of spaced tubularperforated bailies one within the other and arranged to cause gasesowing from said inlet to the outlet to pass both longitudinally betweenthe ballles and through the bafe perforations, means for introducing gasinto one end of the innermost bame, and an imperforate closure for theopposite end o the baftle assembly, and an end of each of said belliesbeing on so that the gas ows from said inlet longitudinally through theinnermost bafiie and then reversely and longitudinally through the spacebetween said innermost baiiie and the next outer baille the discharge ofgas `from said baille assembly being confined to the perforations of theoutermost baille.

5. A muffler comprising a shell having an inlet and an outlet, atransverse wall within the shell between the inlet and outlet, a baleassembly at one side of said wall and including a plurality of spacedsubstantially concentric tubular perforated balles, said wall containingan opening through which gas flows from said inlet into the innermostbaille, the gas thence flowing both longitudinally between the bames andthrough the baille perforations to said outlet, and an imperforateclosure for the end of the baffle assembly furthest from said wall.

6. A mufller comprising a shell having an inlet and an outlet, atransverse wall within the shell between the inlet and outlet, a balleassembly at one side of said wall including an imperforate end closurespaced from said wall, an inner tubular perforated baille extending froma central opening in said wall toward said end closure, a second tubularperforated baille surrounding said inner baille and extending from saidend closure toward said wall, and a third tubular perforated baillesurrounding said second baffle and extend- `ing from said end closure tosaid wall, gas entering said inner baille owing longitudinallytherethrough and thence twice reversing its ow in passing within spacesbetween the ballies to iinally gisfcharge through the perforations insaid third 7. A muller comprising a shell having an inlet and an outlet,a transverse wall within the shell l one side of said wall including animperforate end closure spaced from said wall, an inner tubularperforated baille extending from a central opening in said wall towardsaid end closure, bame means at the inlet side of said opening, a secondtubular perforated baille surrounding said inner baille and extendingfrom said end closure toward said wall, and a third tubular perforatedbaille surrounding said second baille and extending from said endclosure to said wall, gas entering said inner baille flowinglongipassage through the side of the shell directly tudinallytherethrough and thence twice reversing its iiow ln passing withinspaces between the baiiies to finally discharge through the perforationsin said third baille.

8. A mumer comprising a vertically extending shell having an inlet fromwhich exhaust gas passes upwardly within the shell to an outlet throughwhich water may enter and now downwardly within the shell, baflie meansinside the shell, an inclined transverse wall within the shell, andmeans for draining water from above the lower surface of said wallthrough the side of the shell.

9. A muilier comprising a vertically extending shell having an inletfrom which exhaust gas passes upwardly within the shell to an outletthrough which water may enter and iiow downwardly within the shell, atransverse wall within the shell having a gas-passing opening, baillemeans above said wall, and means forming directly above said wall adrain vpassage for withdrawing from the shell water deposited on saidwall.

10. A muiiier comprising a vertically extending shell having an inletfrom which exhaust gas passes upwardly within the shell to an outletthrough which water may enter and flow downwardly within the shell, atransverse wall within the shell having a gas-passing opening, baillemeans above said wall and annularly spaced from said shell, animperforate head closing the top of said baille means, means forming awater drain above said wall, and means for opening and closing saiddrain passage.

11. A muiller comprising a vertically extending shell having an inletfrom which exhaust gas passes upwardly within the shell to an outletthrough which water may enter and iiow downwardly within the shell,baille means inside the shell, an outer shell surrounding the muiliershell and forming therewith a passage through which air iiow is inducedby the discharge of exhaust gases from the muffler outlet, means fordiverting from said baille means the water entering the mumer, and meansfor draining the water through both of said shells.

12. A muiiier comprising a vertically extending shell having an inletfrom which exhaust gas passes upwardly within the shell to an outletthrough which water may enter and ow downwardly within the shell, atransverse wall within the muilier, baille means above said wall andspaced from said shell, an outer shell surrounding the muiiler shell andforming therewith a passage through which air iiow is induced by thedischarge of exhaust gases from the muiiier outlet, and means forming awater drain outlet extending from directly above said wall through bothof said shells. i

13. A munier comprising a vertically extending shell having an inletfrom which exhaust gas passes upwardly within the shell to an outletthrough which water may enter and flow downwardly within the shell, atransverse inclined wall within the muier, baille means above said walland spaced from said shell, an outer shell surrounding the mumer shelland forming therewith a passage through which air iiow is induced by thedischarge of exhaust gases from the mumer outlet, a drain pipe extendingfrom above the lower side of said inclined wall through both of saidshells, and an outside valve for said drain Pipe.

PEI'ER. E. FLUOR.

